On 9/26/07, Terry Jones <terry@jon.es> wrote:
What's the most compact way to repeatedly call a function on a list without accumulating the results?
While I can accumulate results via
a = [f(x) for x in mylist]
or with a generator, there doesn't seem to be a way to do this without accumulating the results. I guess I need to either use the above and ignore the result, or use
for x in mylist: f(x)
I run into this need quite frequently. If I write
[f(x) for x in mylist]
with no assignment, will Python notice that I don't want the accumulated results and silently toss them for me?
Only after the list is completely constructed. List comprehensions are literally 'for' loops with an append call to a method so without extending the peepholer to notice this case and strip out the list creation and appending it is not optimized.
A possible syntax change would be to allow the unadorned
f(x) for x in mylist
And raise an error if someone tries to assign to this.
Go with the 'for' loop as Adam suggested. I just don't see this as needing syntax support. -Brett